This invention generally relates to an output bearing assembly in a vehicle transmission and, more particularly, to an output bearing assembly having an intermediate speedometer sensor.
A transmission of a vehicle typically includes a main section and an auxiliary section which each contain gears to provide several speed ratios on an output shaft. An output bearing assembly mounts the output shaft beyond the auxiliary section. Typically, the output bearing assembly includes a pair of tapered output bearings supporting the output shaft relative to the housing of the auxiliary section. Part of the function of the output bearing assembly is to support and limit radial displacement of the output shaft. Space constraints typically require that the two output bearings be placed relatively close to each other. Because the bearings are in close proximity, conventional output bearings may allow undesirable radial displacements of the output shaft.
In addition, the typical transmission of a vehicle includes a speedometer rotor and a speedometer sensor both located beyond the output bearing assembly. The speedometer sensor measures the rotational speed of the speedometer rotor which is mounted on the output shaft. The sensed rotational speed is used as an indication of vehicle speed.
It would be desirable to provide an output bearing assembly which is better able to reduce radial displacement of the output shaft.
This invention provides an output bearing assembly for a vehicle transmission in which a pair of output bearings are spaced apart and at least one speedometer sensor is mounted between the two output bearings. Generally, by placing the sensor between the bearings, the bearings may be separated by a greater distance without any necessary increase in the total length of the transmission.
Preferably, an output bearing cup spacer integral with a housing of the auxiliary section spaces the bearings. In a second embodiment the output bearing cup spacer is a separate part from the housing. Both the output bearing cup spacer and the housing of the auxiliary section are spaced radially about an output shaft.
The bearings are preferably tapered roller bearings. The output bearing cup spacer is positioned between outer races of the output bearings and a speedometer rotor is mounted around the output shaft between inner races of the output bearings. Most preferably, the spacer extends radially inwardly beyond an outermost surface of the outer races of the bearings.
At least one speedometer sensor is mounted with a first end extending through the bearing cup spacer and spaced adjacent to the speedometer rotor.
The speedometer sensor typically includes a set of external threads to be received in an internally threaded hole provided in the auxiliary section housing. A washer and a nut are threaded onto the speedometer sensor. The speedometer sensor is then threaded into the housing to a predetermined depth and then the nut and washer are tightened against the housing to lock the speeedometer sensor in place. The speedometer sensor is capable of detecting the rotational speed of the speedometer rotor and to thereby enable the speed of the vehicle to be calculated.
The invention provides an output bearing cup spacer for separating the output bearings of the output bearing assembly in the transmission of a vehicle. This increases the distance between the output bearings such that radial displacement of the output shaft is reduced. The total length of the transmission is not increased since the space for mounting the sensor is now between the bearings.
These and other features and advantages of this invention will become more apparent to those skilled in the art from the following detailed description of the presently preferred embodiment. The drawings that accompany the detailed description can be described as follows.